Want to Lose Weight? Exercise Alone Won’t Help You

It’s one of the age-old problems of putting on a few too many pounds: Once you’ve gained them, they don’t seem to want to leave very easily. If you’ve wanted to slim down for a while, or you’re noticing that your clothes aren’t fitting quite as well, it’s time to get a move on. But if you’re thinking that you’ll just start walking a little bit or you’ll do a set or two of crunches to melt away the excess weight that’s not welcome anymore, think again. In fact, several studies show that exercise alone has very little effect on moving the scales in your favor.

There’s a reason “diet and exercise” seems to be a phrase that isn’t split. Despite hearing them together, though, many people can fall into the trap of thinking they can get away with just one. But if you’re one of those people who doesn’t want to part with their beer, bread, or baked goods, you’ll have a tougher challenge ahead of you. Sorry, trying to lose weight (especially if it’s more than a pound or two) has much more to do with what you’re eating. If you become friends with the treadmill but your diet stays the same, those extra pounds can feel pretty secure calling your gut home.

Why exercise doesn’t work

A 2013 study published by Population Health Metrics is just one of several that found exercise alone does very little to budge that number on the scale. The weight of men and women in the United States has increased dramatically over the past 50 years, and men now weigh an average of 195.5 pounds, 30 pounds more than the average in 1960. Women weigh less, but at an average of 166 pounds now weigh about what men did in 1960. But the study mentioned above found that even when people increased their exercise regimens, obesity rates continued to rise. “There was a low correlation between level of physical activity and obesity in U.S. counties,” the study’s authors wrote. “Our study showed that increased physical activity alone has a small impact on obesity prevalence at the county level in the U.S.”

Another study published in 2014 conducted a meta-analysis of eight other studies that used different weight loss methods for their respective participants. (In other words, it was a study of other studies.) The analysis included programs that were diet-only, exercise-only, and a combination of both to see which programs yielded the most weight loss. “Programs based on physical activity alone are less effective than combined BWMPs [behavioral weight management programs] in both the short and long term,” the study concluded.

You can blame simple math for why exercise often isn’t as effective in weight loss compared to diet. To lose weight, you need to expend more calories than you eat. (This should be reminding you of your eighth-grade health class.) While exercising does help you increase the calories your body is burning, it’s often not nearly enough compared to the calories you’re consuming. People who are willing to cut back on food see much bigger results, much faster. By the way, changing your diet doesn’t necessarily mean “dieting” — there are other healthy ways to cut back on your food intake.

Juciy burger with tomatoes, lettuce, and onion | iStock.com

Often the issue lies in another math error — people believe their new exercise routine is burning many more calories than it actually is. “Thirty minutes of jogging or swimming laps might burn off 350 calories. Many people, fat or fit, can’t keep up a strenuous 30-minute exercise regimen, day in and day out. They might exercise a few times a week, if that,” explained Indiana University School of Medicine professor of pediatrics Aaron E. Carroll in a column for The New York Times. “Or they could achieve the same calorie reduction by eliminating two 16-ounce sodas each day.”

So far we’ve made exercise out to be the bad guy, perhaps making you feel better about forgoing that run earlier today. But this is where exercise comes back in to play: It might not have the biggest impact on weight loss, but it does definitely help when it’s combined with a slimmed-down dinner plate. The same meta-study mentioned above found that over a period of a year to 18 months, people who combined diet and exercise lost more weight than those who focused only on their diet.

“For most people, it’s possible to lower their calorie intake to a greater degree than it is to burn more calories through increased exercise. That’s why cutting calories through dieting is generally more effective for weight loss. But doing both — cutting calories and exercising — can help give you the weight-loss edge,” Dr. Donald Hensrud explains on the Mayo Clinic’s website.

The food industry’s role

Food at a grocery store | iStock.com

Hensrud also said that exercise helps to maintain weight loss you have achieved, even if you slip up and have that extra cookie. It’s also a good idea to keep exercise a part of your routine — or add it as a new habit. Though the Population Health Metrics authors disputed that exercise will necessarily help with weight loss, they did write that it has other positive effects such as reducing cardiovascular diseases and diabetes.

But the question is there — why are so many people under the impression that exercise will work wonders, no matter what they eat? That blame doesn’t lie with mathematics, but instead with the food industry, according to three doctors who published an op-ed in the British Journal of Sports Medicine last April. In the article, the doctors compared many in the food industry to Big Tobacco, saying they mislead consumers by making them believe they can drink soda and consume fatty foods as long as they run a little bit, too.

One of the authors, according to the BBC, explained it like this: “An obese person does not need to do one iota of exercise to lose weight, they just need to eat less. My biggest concern is that the messaging that is coming to the public suggests you can eat what you like as long as you exercise. That is unscientific and wrong. You cannot outrun a bad diet.” Several public officials contested the op-ed, though many of them notably have close ties with the food industry. So do lace up your running shoes, but put the hamburger down first.